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AES encrypt and decrypt

Encrypt and decrypt text with AES-256-GCM in your browser. Your passphrase is stretched with PBKDF2; output bundles salt, IV and ciphertext.

Encrypt or decrypt

AES-256-GCM with a PBKDF2-derived key. Needs a secure context (HTTPS or localhost).

Output format: Base64(salt).Base64(iv).Base64(ciphertext). Keep the whole string to decrypt later. Needs a secure context (HTTPS or localhost) for the Web Crypto API. Nothing is uploaded.
AES-256-GCM

The result appears below. Decryption fails loudly on a wrong passphrase.

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AES-256-GCM

AES-256 with Galois/Counter Mode is the modern standard for symmetric encryption: it encrypts with a 256-bit key and appends a 128-bit authentication tag, so decryption fails if even one bit was tampered with. This page derives the key from your passphrase with PBKDF2-HMAC-SHA-256 (100,000 iterations) and a fresh random salt and IV per encryption.

Output format

The output is three Base64 parts joined by dots: salt, initialization vector, then ciphertext with its authentication tag. Keep the whole string; decryption needs all three parts plus the exact passphrase. A wrong passphrase fails authentication instead of returning garbage.

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AES Encrypt FAQs

Is AES-256 still secure?
Yes. No practical attack on full AES-256 exists; the best known attacks are barely better than brute force. It is approved for top-secret data and used worldwide.
What if I forget the passphrase?
The data is unrecoverable. There is no backdoor and no key escrow; that is the point of encryption. Store passphrases in a password manager.
Why is the output different every time?
A fresh random salt and IV are generated per encryption, so identical plaintexts produce different ciphertexts. This prevents attackers from spotting repeated messages.
Can I decrypt messages from other tools?
Only if they use the same format: PBKDF2-HMAC-SHA-256 with 100,000 iterations, AES-256-GCM, and salt.iv.ciphertext Base64 layout. Most tools differ, so treat this as self-contained.
Is my passphrase sent anywhere?
No. Key derivation and encryption run in the Web Crypto API locally; the passphrase never leaves your device.
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